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This design is among many low-tech alternatives to modern appliances and processes mentioned in book The Knowledge: How to Rebuild Civilization in the Aftermath of a Cataclysm. It was not successful because of already established industry of refrigerators that were good enough. The book is excellent.
Thanks for the book, I'm adding it to my list
You may also enjoy How To Invent Everything[0], from the creator of SMBC Comics. The frame device is that it's a manual that comes with your time machine, only to be used if you get stranded. I thought it would be a fun flip-through but it's delightfully dense, with fun comments on when, where, and why you'd need want/need to invent something depending on "when" you get stranded in time.
Mild sidenote: How to Invent Everything is by Ryan North, the cat behind Dinosaur Comics; Saturday Morning Breakfast Cereal is done by Zach Weiner, a different person.
Milder sidenote: SMBC was created by Zach Weinersmith. Presumably his ancestors made the weiners.
I believe he changed his name when he married to incorporate his wife Kelly's
That might be the case! I haven't read SMBC regularly for a very long time, so if there was a name change in the past, i dunno, five years or something, I probably wouldn't have noticed!
Oof, you're correct! I totally mixed my comics up. Both are fantastic, pithy creators.
From the order page:
“To ensure that your future self is enjoying this book as we speak, simply click on one or more of the following links:”
Love it!
According to the article the patents were bought by Electrolux. It could be this was just to block this technology from being adopted.
No, it has been actually deployed and is commercially sold as heat recovery chiller.
The problem is an much lower efficiency than compression refrigerators, some of which could be regained by tuning the liquids used in the system. That is not a problem when you're working with waste heat though. (E.g. solar thermal, recovery from solar concentrated, cogeneration, geothermal.) The other problem is that it has to be perfectly leak checked or it does not work at all, where in compression leakage just reduces efficiency - and there's much less piping that has to be pressure sealed.
COP of maybe 1.3 for best designs is available, compared to say 5 of a top of the line screw chiller, 7 of a rotary chiller and 3 of very good heat pump. (Maybe COP could be pushed a bit higher with exotic liquids. But the economics of this endeavor are suspect. Current top efficiency liquids are water-ammonia/lithium bromide-water dual loop. It is not safe compared to HFCs.)
It starts making sense when the installation is building sized, because maintenance is cheap compared to an electric chiller.
I thought this is how RV (propane) refrigerators work? Or, am I confusing this with a different, but similar system?
Absorption refrigerators are commonly used in Recreational Vehicles (RVs), campers, and caravans because they can be powered with propane fuel, rather than electricity.
No confusion, that's how the refrigerators work in our '81 VW camper and our much more modern Sprinter RV. Last I was in a position to know such things, many Amish use absorption fridges as well.
You mean fridges that use propane as fuel or ones that use it as a freon?
As a fuel. And yes, it's the same principle.
The patent is long expired. It has not seen widespread use because the efficiency is far below modern units. It does see some specialized use in situations where you have heat but not electricity--the conversion of heat to electricity is not a very efficient process, this can make it competitive.
There's a good write-up here: https://www.wired.com/story/einsteins-little-known-passion-p...
It's a bit conspiratorial to suggest this was technology bought and buried by Big Air Conditioning
It would be interesting to know the practicality of this fridge and its efficiency in relation to more conventional fridges.
The practicality is answered by the fact that many/most recreational vehicles you see going down the road will use a refrigerator like this. As for power efficiency, in comparing compressor fridges to absorption, I think a well-design compressor fridge will use less electricity (absorption fridges can use an electric heater, too), but not by a huge margin. But if your efficiency question is about how well it keeps things cool, ours will make ice cubes when it's in the 80s F.
The last time I researched this, absorption fridges when run on electric resistance heating use on the order of 300% more energy.
But of course in the case of an RV where you are on a car battery but have a large propane tank, they make sense in terms of energy storage.
With the more cost effective Lithium batteries the higher end RV coaches have all eliminated the absorption fridges and gone with compressors and bigger batteries.
But of course in the case of an RV where you are on a car battery
Most RVs have a "house battery" that usually dwarfs a car starting battery, usually multiples. But even then, running a compressor fridge takes more battery than our little RV has room for (including the roof space for solar to refill those batteries). I think that's a lot of the reason you see compressor models primarily on larger/more costly rigs: they've got room for the batteries, and they don't boondock much. Lithiums just save weight and space (more usable electrons in the same size). If you've got a Class A (rock band touring rig), just line that thing with as many lead-acids as you need. Which is what the manufacturers do; I don't know of a single company installing lithium batteries stock.
Are you saying that they run on a propane flame in the RV?
Correct! Any heat source of sufficient temperature will work, but propane is convenient. I recently took a ferry in Idaho; before loading, people in RVs were told to turn off their refrigerator to reduce fire risk. Searching for "absorption refrigerator diagram" (or checking out the wikipedia page) should provide useful information.
Thanks.
Recreational vehicles as in RVs? They don't use compressor fridges? Is it because the Einstein ones are lighter?
Ours was built in 2018, uses an absorption fridge. They're lighter (assuming that you're going to carry propane anyway), and they don't need electricity (though they can run on it). Though you can get compressor models that run on 12VDC, I'm guessing most rigs with compressors don't park far from an outlet. But I'm not the one to ask on that. I do know that when we're running off solar and batteries, it's nice to eliminate one more thing draining the batteries.
Thanks.
I'm not sure, but RV refrigerators work the same way, by heating Ammonia (via propane usually). because the heat source is typically propane, its great for locations without electricity.
Looks like you're talking about https://en.wikipedia.org/wiki/Icyball
it says its used in RV applications, but I don't see how the described system uses propane to heat a portion of the closed loop.
If you are looking for post-apocalypse design options, or even practical solutions for current real world problems to try to avert the apocalypse, there is also a zeer, aka "pot in pot refrigerator."
> ... requires only a heat source to operate.
Nope. It also requires a heat sink.
Belated edit: See https://en.wikipedia.org/wiki/Einstein_refrigerator#/media/F...
> ... Intermediate Condenser ... Cooling Water ...
NB / OT: I'm getting NET::ERR_CERT_AUTHORITY_INVALID for wikipedia.org currently.
Update: Working with Wikipedia on this. They pushed a new set of certs earlier today. There may be issues with some UAs. My old, stale Android (5.0.2) and Chrome (76.0.3809.132) aren't happy with Wikipedia or Globalsign's root test URL:
https://valid.r5.roots.globalsign.com/
(Also an ERR_CERT_AUTHORITY_INVALID)
I suspect a stale CA list somewhere.
This has been resolved, working through Wikipedia:
We've deployed a cross-chained intermediate back to the older R3 root now, which we believe will fix this for you (and other such clients). It has a small perf impact on all of the modern clients, but I think Android 5 isn't quite old enough yet that we can just ignore its compatibility.
(Via email.)
Is there an actual explanation of how the design fridge works?
They received the equivalent of $10k for their patent. Doesn’t it cost about $25k today to file a patent?
I imagine Einstein, given his first job, could file a lot of the paperwork himself ;)
Einstein used the experience he had gained during his years at the Swiss Patent Office to apply for valid patents for their inventions in several countries. The two were eventually granted 45 patents in their names for three different models.
The cost of an external parent attorney, maybe (but even that is exaggerating). The actual cost to file and own a patent is much smaller.
Technically, filling a patent is cheap. Less than 1000$. What is expensive is elaborating the patent document which requires an expert. It's their fee that is expensive